Model airplane construction



Dec. 22, 1959 H. A. BERGSTRAND 2,917,865

MODEL AIRPLANE cons'muc'rrou Original Filed March 18, 1957 ATTORNEY United States Patent IO MODEL AIRPLANE CONSTRUCTION Harold A. Bergstrand, East Moline, Ill., assignor to Stromberg-Becker Manufacturing Co., Moline, 111., a corporation of Illinois Original application March 18, 1957, Serial No. 646,812, now Patent No. 2,870,568, dated January 27, 1959. Divided and this application December 10, 1957, Serial No. 701,862

8 Claims. (Cl. 46-76) This invention relates to a toy or model airplane and more particularly to improvements in landing gear structure. This application is a division of copending application Serial No. 646,812, filed March 18, 1957, now Patent 2,870,568.

The invention features novelty and simplicity in construction through the use of composite and bracing structure enabling the exploitation of sheet material as the basic material of which the ship is constructed, to the end that the ship may be furnished in kit form for assembly into a model that is attractive as a display item as well as having good flight characteristics and resistance to damage in crashes. In a preferred embodiment, the ship is constructed primarily of sheet material such as polystyrene, which itself has certain structural advantages in addition to its ability to lend itself to mass production methods as well as being economical, light in weight, attractive and easy to cement, but which also has certain structural disadvantages where the sheet portions are of substantial area. Therefore, it is a feature of the invention to utilize tubular or hollow structure to enhance the strength of the material. It is a primary object to provide a novel landing gear structure including improved strut means, mounting of intermediate landing gear strut structure within the fuselage, reenforcement of said intermediate structure by attaching elements of rigid section, reenforcement of the strut legs by concealed wire means or the like; and such other features and objects, inherent in and encompassed by the invention, as will appear from the ensuing detailed description of a preferred embodiment of the invention as illustrated in the accompanying sheets of drawings, the several figures of which are described below.

Figure 1 is a perspective of the complete ship.

Figure 2 is an enlarged section on the line 2-2 of Figure 1.

Figure 3 is a section on the line 33 of Figure 2.

Figure 4 is an enlarged exploded perspective of a landing gear support.

Figure 5 is an enlarged section on the line 5-5 of Figure 2. W

Figure 6 is an enlarged section on the line 6 6 of FigureZ. g l 7 p,

- Figure 7 is an enlarged perspective of a strut-retaining member.

The ship as it appears in Figure 1 has much the general appearance of a conventional airplane, actually being a scale model to a major extent of a well-known full-sized model whose identity is of no moment here. As such, it has a fuselage 20, right and left wing assem blies 22, and tail assembly 24 including right and left elevators 26 and a rudder or fin 28. The fuselage is tubular, here shown as made up of right and left complementary halves appropriately flanged to be cemented or otherwise secured together along a joint 30 that lies in the upright fore-and-aft median plane of the ship. The tubular character of the fuselage results from its formation of formed sheet material, one suitable type 2,917,865 Patented Dec. 22, 1959 of which is polystyrene, which may be commercially vacuum-formed. The designation here of this material and/or its forming process does not of course exclude others, but that referred to has been selected because of its accepted use in production of planes of the nature described.

The fuselage thus has an under or belly portion 32 which provides a pair of opposite generally upright foreand-aft side walls 34. Since these are symmetrical at both sides of the median plane along the joint 30 and r are further symmetrical relative to components'to be described, the ship will be further dealt with as from one side only, thus avoiding repetition. i

In the formation of the fuselage halves, each side is provided with a fore-and-aft elongated exterior mount ing pad 36 of airfoil shape as seen in elevation, and these respectively mount the wing assemblies 22. The elevators 26 are mounted via similar pads, one of which appears at 44 and which, having the configuration and other characteristics just outlined need not be further described. Each elevator pad 44 mounts its wing-like elevator element 26, which is of sheet-like construction, having here a single-thickness concave-convex top wall 46 extending outwardly from its mountingpad. The mounting of the wing and tail assemblies forms the subject matter of the above-identified copending application. In a commercial embodiment of the ship disclosed, the various components are vacuum-formed in a single sheet and are cut out therefrom for assembly.

Each wing assembly has at its under surface a recess 88 and a tubular strut 90 has its outer or upper end received in and cemented to the pocket 88 and has its inner or lower end received in and cemented to the fuselage via a fuselage pocket 92 integrally formed in the fuselage wall 34. The strut is preferably made up of a pair of complementary halves cemented together. The pockets are an aid in assemblng the components as well as contributing to the maintenance of the respective joints.

' The significant feature of novelty is the landing gear mounting, which here takes the form of a pair of wire elements 98. Since these are symmetrical, only one and its mounting will be described. The Wire has a strut or leg 100, which is arranged here in downwardly and cut wardly inclined relation to the median plane of the ship and this leg terminates at its lower or outer end as an integral transverse axle 102 for journaling a landing wheel 104. The leg 100 has at'its upper or inner end a portion 106 in the form of an L made up of a transverse part .108 and a fore-and-aft part 110. In keeping with the concealment of components and joints likely to'detract from the authenticity of the model, the fuselagewall 34 is apertured at 112 to receive the wire 98, so that the leg 100 is external to and the L 106 is interiorly of the wall. The wall has a slight transverse curvature and the L part 108 conforms thereto. The fore-and-aft part110 of the L lies along the fuselage and the L portion is secured to theinterior surface of this fuselage by, means L-s haped groove 116 in its under surface to overlie and to receive the L-shaped part of the wire. Again cement is used as the adhesive to secure the member 114, with its groove 116 down, since the material of the member 114 and that of the fuselage may be the same. The transverse part 108 of the L lies in the transverse part of the groove 116 and restrains the leg against lateral displacement and the fore-and-aft part lies in the fore-and-aft part of the groove and performs the same function relative to fore-and-aft displacement. In other words, the L of the wire is sandwiched between the upper interior surface of the fuselage and the under portion of the member 114. In order to avoid the necessity of pro wall I ducing rights and lefts, the wires for the two sides of the ship may be identical and when assembled, the fore and-aft part of one extends forwardly and the other rearwardly, and the members 114 are identical but are rotated 1 80 as respects each other when assembled. in addition tosecurin'g and confining the wire Ls 106, the two members operate as a cross brace in the belly section of the fuselage. Theleg of the WiI'6'98'1S concealed by a tubular strut housing 118, preferably made up of a pair of complementary halves cemented together and forming a housing that embraces the wire. An intermediate portion of the leg is of zig-zag configuration as at 101 (Figure 4) and its fore-and-aft disposition within the housing (Figures 2 and 6) prevents the housing from turning about the axis of the wire leg 100. Thus, the actual support of the landing gear is via the wires, and the strut housings, although carried by the wires, do not interfere with the flexibility thereof.

' Another instance of the exploitation of wire as a stiffener is shown at 29 in the fin or rudder 28 (Figure 1).

The objects and general nature of the improvements wrought here have been elaborated along with the description. Features and objects not so enumerated will readily occur to those versed in the art, as will many modifications and alterations in the preferred inventive embodiment disclosed, all of which may be achieved without departure from the spirit and scope of the invention.

What is claimed is:

1'. In a toy airplane: a hollow fuselage of relatively light-weight flexible material having a belly portion and opposite side wall portions adjoining said belly portion, each Wall portion having an aperture therethrough and said apertures being transversely alined; a pair of tubular landing gear legs, one extending downwardly from each side wall portion and having an upper end adjacent to the aperture in said wall portion; landing gear support structure of material relatively stiffer than the fuselage and including'an intermediate part traversing the fuselage wholly interiorly thereof and lying on and in contact with the belly portion and extending oppositely outwardly through the apertures and integral outer parts extending respectively through and enclosed at least in part by said tubular legs; and means interiorly of the fuselage and rigidly securing said intermediate part to the belly portion of the fuselage.

2. In a toy airplane: a hollow fuselage having a foreand-aft wall including interior and exterior surfaces and having transversely spaced apart and alined apertures therethrough; a pair of wire elements extending respectively through said apertures and each element having a leg outside said Wall and an integral bent portion within the fuselage and lying along the interior surface of said wall; means within the fuselage and securing said bent portions to said wall at the interior surface thereof; and said bentportions being contoured to fit said wall and disposed over a substantial area of said interior surface for affording relatively rigid fuselage-to-element mountings so as to brace said legs against deflection relative to the fuselage except for resiliency in said legs.

3. The invention defined in claim 2, in which each bent portion is in the form of an L lying along said interior surface, a portion of each L lying transverse to the fuselage and an integral portion of each L lying fore-and-aft;

and securing means overlies a substantial area of said interior surface to afford both lateral and fore-and-aft reenforcement of the fuselage at said fuselage-to-element mountings.

4. The invention defined in claim 3, in which: said securing means includes a pair of members juxtaposed over and having under faces secured to said interior wall surface, each member having an L-shaped recess therein to receive the L of the respective wire element.

5. In a toy airplane: a fuselage having a fore-and-aft Wall; a pair of wire elements, each including a leg projecting outwardly from said wall and having a bent outer end forming an axle and a bent fuselage-proximate end in the form of an L lying against and contoured to fit said wall, each L including a portion transverse to the fuselage and an integral portion disposed fore-and-aft; and means securing said L to the Wall, said means being relatively rigid and having a pair of L-shaped recesses therein respectively receiving the Ls of the wire elements and sandwiching said Ls between said means and said wall.

6. In a toy airplane having a fuselage, a landing gear strutassembly comprising: an elongated relatively stiif but resilient thin metallic leg connected at one end to and extending from the fuselage and having an axle at its other end; a sleeve of non-circular section and of relatively lightweight material extending between the fuselage and the axle and loosely enclosing said leg; and said leg within said sleeve being deformed to engage the interior of said sleeve to limit rotation of said sleeve relative to the leg about the lengthwise axis of said leg.

7. In a toy airplane having a fuselage, a landing gear strut assembly comprising: an elongated relatively thin leg connected at one end to and extending from the fuselage and having an axle at its other end; a sleeve of noncircular section extending between the fuselage and the axle and loosely enclosing said leg; and said leg within said sleeve being deformed to engage the interior of said sleeve to limit rotation of said sleeve relative to the leg about the lengthwise axis of said leg.

8'. In a toy airplane having a fuselage, a landing gear strut assembly comprising: an elongated relatively thin leg connected at one end to and extending from the fuselage and having an axle at its other end; a sleeve extending between the fuselage and the axle and loosely enclosing said leg; and means on said leg within said sleeve to engage the interior of said sleeve to limit rotation of said sleeve relative to the leg about the lengthwise axis of said leg.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain May 4, 1939 

